/Engine/Source/Runtime/Core/Public/Misc/StringBuilder.h
template<typename AppendedCharType, std::enable_if_t< [TIsCharType](API\Runtime\Core\Traits\TIsCharType)< AppendedCharType >::Value > *> [BuilderType](API\Runtime\Core\Containers\TStringBuilderBase\BuilderType) & AppendChar ( AppendedCharType Char )